In general, a vehicle body is manufactured at the first stage of a vehicle manufacturing process. Further, the vehicle body is carried to a body factory after panels are produced through various presses and the panels are assembled, thereby producing a BIW (body in white).
The BIW is a frame of a vehicle that is manufactured by welding panels, without detachable doors, a hood, a power train, and a chassis, and is not painted. The frame of a vehicle includes pillars that function as a support.
The pillars refer to a part of the frame of a vehicle, supporting the roof. Further, the pillars are classified into a front pillar, a center pillar, and a rear pillar, sequentially from the front of the vehicle. The front pillar, center pillar, and rear pillar are also called an A pillar, a B pillar, and a C pillar, respectively.
Recently, stability performance has attracted attention, among items of performance of a vehicle. Ultra high strength steel has been increasingly used in the automobile industry to reduce the weight of a vehicle body and improve safety in a collision, and, as one of ways of forming ultra high strength steel of 1500 MPa, there is hot stamping. That is, recently, a structure in which one or more of the front pillar, the center pillar, and the rear pillar and a side sill are integrally molded as a single part by using a hot stamping process has been adopted.
In order to improve shock-absorbing performance with respect to a load applied to the vehicle, rigidity of the center pillar and a side sill that extends in a length direction at lateral sides in a width direction of the vehicle body and thus connected with the center pillar need to be enhanced, and a connection structure between constituent elements of the vehicle body to ease distribution of the load is required.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.